Field of the Invention
The invention relates to an apparatus for the continuous cultivation in suspension of microorganisms, and also of animal and vegetable cells, in a culture liquid, which apparatus contains a cultivation tank provided with a stirring device, which tank is provided with an inlet for fresh cultivation medium and an outlet for used culture liquid, which tank contains a rotating separating device for separating suspended cells or cell-carrying particles from the culture liquid passed through the separating device, which separating device is provided with a collecting space for culture liquid rendered essentially free of cells into which the outlet for the culture liquid, rendered essentially free of cells, debouches.
For cultivating cells and other microorganisms in a culture liquid it is known that use is made of the so-called continuous perfusion system. In said system a rotating filter is used in a so-called fermenter or bioreactor, which filter has a pore size which is smaller than the diameter of the microorganisms, or cells or cell-carrying particles in the culture liquid which have to be separated. In this process medium is continuously supplied to the cultivation tank, the so-called fermenter or bioreactor, while culture liquid which is essentially free of cells is removed from the collecting zone located inside the filter. In this manner relatively high concentrations of microorganisms, or cultivated cells can be obtained along with the high product concentrations associated therewith in the culture liquid drained off.
A rotating filter is used inorder to prevent obstruction of the filter surface as far as possible- Centrifugal and shearing forces are exerted on the cell material deposited against the outside of the rotating filter as a result of which said cell material can at least to a large extend be removed from the filter surface. In practice, however, it has emerged that the rotating filters nevertheless become blocked within, in many cases, an undesirably short period, as a result of which limits are imposed on the product yield.